In conventional technology, coal is used to produce coal gas, natural gas, or used to produce gas by coking at high temperature, medium temperature or low temperature. However, the above-mentioned technology is required to block pulverized coal or sift lump coal, as a result, it increases the cost of raw material, or cause the produced gas without a high heat value, a big additional value, and a significant economy and social benefits. The heating methods of furnace can be classified as external-heating style, internal heating style and hybrid-heating style. Specifically, the heating medium in external-heating furnace is not contact directly with raw materials and heat is conducted from furnace wall. The heating medium in the internal-heating furnace contacts with the raw materials directly, and the heating methods are classified as solid heat carrier style and gas heat carrier style according to different heat mediums.
At present, there are two kinds of conventional coal decomposition equipments, one of which has an up-draft kiln structure. The up-draft kiln structure is used for combusting flue gas and combustible gases produced by coal, which has low gas purity and a low additional value, as well as partially discharge of gas. This results in a significant resources wasting and environmental pollution. Another kind of coal decomposition equipment has a shaft kiln structure. Under the structure, coal lumps are placed on clapboard with holes, and a heater is provided above the coal lumps. Because the coal lumps on the clapboard are accumulated to a certain thickness, they cannot be uniformly heated and decomposed, and are required to be cyclically heated and decomposed by the decomposed gas. More importantly, since the large amount of holes for ventilation and circulatory function provided on the clapboard, pulverized coal can leak from the holes. To avoid the condition, it is necessary to process the pulverized coal into coal briquette when introducing it into the shaft kiln. Thus, it will increase the cost of pulverized coal decomposition, and reduce the economic benefits because the pulverized coal cannot be directly used for coal decomposition.
There is a conventional coal decomposition equipment, which includes an airtight kiln body with an inlet and an outlet. The airtight kiln body has a flame gas pipeline heating means. A channel for impelling and decomposition coal is formed between the flame gas pipeline heating means and the inner wall of the kiln body. A collecting pipe for coal decomposition gas is provided on the kiln body to communicate with the channel for impelling and decomposing coal. Although the coal can be decomposed and separated to a good purity, however, the rotary kiln body limits the products' yields. In addition, it is no ideally enough about the effect of heating the pulverized coal outside the channel through the internal heating channel, and it cannot satisfy the production requirements of the fast decomposition and separation of coal.